A quick trip down to B&Q to purchase large sheets of polystyrene and 7 sheets of hardboard to clad the inside of the roof.

Not surprisingly 4ft x 8ft sheets of hardboad and polystyrene are not going to go into the back of my wifes XC90 so I took advantage of the cutting service in the store to get all the boards cut to the desired length. I kept all the off cuts as these will be useful for future terrain builds.

The polystyrene had to be broken up in to pieces just to fit them into the car.

The roof as you see in the picture above has had the poly stuff forced into the rafters. Its 4.5cm thick so should provide plenty of insulation in the winter.

Over the poly I added the hardboards. These were fixed with standard screws and I used some of my 25mm washers to give the fixings greater strength. Having put up two boards I realised that it would be more practical to paint the others outside before fixing. Hence why some are white and some are brown. Eventually all the roof and walls inside the shed will be white.

Some unpainted and painted boards....

AS you can see from the picture below the cabin is now full of white polystyrene beads.

By the end of this week I should have the ceiling completely finished. Ill then start on the walls.

Not sure about rainfall in your location but here in Bonnie Scotland it does occasionally stop.

When I built my shed I ran a sheet of polythene in between the shed formers/insulation and the inner layer of weatherboard. This provides a waterproof barrier between the outside of the hut and the inside. It maybe too late for you to consider that now.